The operation process of diesel generator sets

The operating principle of diesel generator sets

A diesel generator set uses diesel as fuel, and the clean air filtered by an air filter in the cylinder is fully mixed with high-pressure mist diesel injected by the fuel injector, resulting in a rapid increase in temperature. When the ignition point of diesel is reached, the diesel is ignited, the mixed gas burns violently, the body volume rapidly expands, and the piston is pushed down, which is called doing work. Due to the fact that diesel engines have multiple cylinders, each cylinder works in a certain order, and the thrust acting on the piston is converted into the force that drives the crankshaft to rotate through the connecting rod, driving the crankshaft to rotate continuously.

The synchronous AC generator matched with the diesel engine is installed coaxially with the diesel engine crankshaft, and the rotation of the diesel engine crankshaft drives the generator rotor to rotate. Using the principle of electromagnetic induction, the generator will output an induced electromotive force, which can generate current through a closed load circuit.

The above is the most basic power generation principle of diesel generator sets. During the power generation process, a series of controls, protectors, and circuits are required to output the most stable and usable electricity.

The working principle of synchronous generators

The basic working principle of synchronous generators includes the following aspects.

1. Establishment of magnetic field. During the operation of the generator set, the excitation winding establishes an excitation magnetic field with the same polarity through direct current excitation current, that is, the main magnetic field is established.

2. Cutting motion. The prime mover, diesel generator set or gasoline generator set drives the rotor to rotate, and the excitation magnetic field of the same model rotates along with the shaft and sequentially cuts the windings of each phase of the stator.

After the operation of the current carrying conductor generator, the three-phase symmetrical current group acts as the power winding, which is called the carrier of induced electromotive force or induced current.

4. Generation of alternating electromotive force

The working principle of synchronous generators is actually the principle of electromagnetic induction. By the relative motion between the rotor magnetic field and the stator winding, mechanical energy is converted into electrical energy. When the rotor is driven by the prime mover, the rotor magnetic field and stator conductor move relative, that is, the conductor cuts the magnetic path, thus generating induced electromotive force in the conductor. Its direction can be determined according to the right-hand rule of u. Due to the position of the rotor magnetic poles, the conductor cuts the magnetic field lines in a vertical direction. So at this point, the induced electromotive force in the stator winding is maximum. When the magnetic pole rotates 90 degrees, the magnetic pole is in a horizontal position, the conductor does not cut the magnetic field lines, and the induced electromotive force is zero. The rotor is rotating at 90 degrees, and the induced electromotive force in the stator winding cuts the magnetic field lines in a vertical direction, causing the induced electromotive force to reach its maximum value, but in the opposite direction as before. When the rotor rotates another 90 degrees. The induced electromotive force is also zero. In this way, when the rotor rotates for one cycle, the induced electromotive force of the stator winding also undergoes positive and negative changes. If the rotor rotates continuously and uniformly, a periodic and constantly changing AC electromotive force will be induced in the stator winding, and the AC current can be output through the lead wire.